JPH0219557B2 - - Google Patents

Description

[Detailed Description of the Invention] [Summary] A cassette-shaped magnetic bubble memory containing a bubble memory device, etc., in which a conductor layer connected to a ground signal terminal is placed in a cassette with the bubble memory device wrapped together with an insulating sheet. By housing the device, damage to the device due to contact with objects charged with static electricity is eliminated.

[Industrial application field]

The present invention is a cassette-shaped magnetic bubble memory (hereinafter referred to as
(referred to as a cassette memory), and particularly relates to an anti-static structure for a cassette memory.

Bubble memory devices have excellent features such as the stored information is non-volatile and can be easily rewritten, they are highly reliable as they are solid-state devices with no mechanically moving parts, and they are small and can be mounted on printed circuit boards with high density. However, its use is rapidly expanding along with IC memory and floppy disks.

In particular, NC equipment, robots, production control terminals,
Confucian devices are rapidly increasing in use as file memories and program loaders for POS terminals, office automation equipment, and various other terminals.

In order to make such a bubble memory device easily portable like a floppy disk or cassette tape, a cassette memory has been proposed in which the device is housed in a case and attached to and removed from the main unit. It is used in various devices.

Since this cassette memory is carried by a person, it is required to be particularly small and lightweight, and consideration should be given to static electricity that may accumulate on the human body.

[Conventional technology]

The bubble memory device contains a bubble memory chip, a bias magnet, a magnetic field shunt plate, an X/Y coil that generates a rotating magnetic field to drive the bubble, and information stored in the bubble chip by the mobile phone in a soft magnetic metal shield case. It is well known that the structure accommodates an erase coil for erasing everything.

In addition, a memory system using a bubble memory device has a direct peripheral circuit (also called a linear circuit) that directly operates and controls the device using analog signals, and a direct peripheral circuit that operates and controls the device directly according to information write/read instructions from the host system. It is also well known that indirect peripheral circuits are required to control the output using TTL (transistor, transistor logic) level digital signals.

These direct peripheral circuits include a coil driver circuit that operates and controls the bubble memory device by supplying a predetermined current value, that is, an analog signal, to the drive coil and memory chip, a function driver circuit, and a detector inside the bubble memory chip. A few mm
It includes a sense amplifier circuit that amplifies the V sense output voltage and converts it to a TTL level. In addition, the indirect peripheral circuit is a bubble controller circuit,
According to information write/read commands from the host system, various control digital signals are input directly to the peripheral circuits to control the operation of the bubble memory device, and digital sense signals are directly input from the peripheral circuits (sense amplifier circuit). output to the host system.

By the way, conventional cassette memory
As disclosed in ``Publication No. 56098'' and ``Publication No. 56099 of Sho 56,'' a bubble memory device and an external connection connector are mounted on a wiring board, and this is mounted in a cassette case made of plastic or some metal. It is housed and configured within. In addition to the bubble memory device, some wiring boards directly incorporate peripheral circuits (sense amplifier circuits) and the like.

The cassette memory thus constructed can be used in a detachable manner by being inserted into and removed from a receiving connector of a magnetic bubble memory device provided with direct peripheral circuits and indirect peripheral circuits.

FIG. 6 is a schematic side sectional view of a conventional cassette memory.
A wiring board 6 for connecting a plurality of contacts 4 whose intermediate portions are supported by the connector 3 and a plurality of lead terminals 5 led out from the front and rear end faces of the device 2 is housed in a cassette case 7. has been done.

The cassette memory 1 includes a metal plate or a metal case for magnetic shielding in the bubble memory device 2 or the cassette case 7, so that the bubble memory device 2 operates normally and protects written information against external magnetic fields. However, sufficient consideration was not given to the possibility of contact with objects charged with static electricity.

[Problem that the invention seeks to solve]

The present invention eliminates the possibility that, for example, when a worker who is charged with static electricity comes into contact with the bubble memory device, a discharge current of static electricity flows through the bubble memory device, damaging the bubble memory chip and destroying the written information, thereby providing a highly safe cassette-shaped device. It provides a magnetic bubble memory.

[Means for solving problems]

In FIG. 1, a schematic side sectional view showing the basic configuration of the present invention aimed at solving the above-mentioned problems, the same reference numerals are used for parts common to FIG. 5.

The above problem is solved at least in the bubble memory device 2 which has a bubble memory chip, a bias magnet drive coil, etc. inside a soft magnetic metal shield.
, an external connection connector 3, a wiring board 6 connecting the contacts 4 of the connector 3 and the lead terminals 5 of the device 2, an electrostatic protection conductor 13 of the device 2, and the wiring board 6 and the device. 2, a cassette case 7 that accommodates the connector 3 and the conductor 13, and a ground terminal 12 that is connected to the outside earlier than the external connection of the contact 4, and the conductor 13 is connected to the ground in the cassette case 7. terminal 12
In the cassette-shaped magnetic bubble memory connected to the wiring board 6, the conductor 13 is formed by depositing a metal film 28c on one side of the insulating sheet 28, and the device 2 is connected to the wiring board 6 so that the metal film 28c is on the inside. This problem is solved by a cassette-shaped magnetic bubble memory which is housed in the cassette case 7 in a state of being wrapped together with the magnetic bubble memory.

[Effect]

According to the above means, even if an object charged with static electricity comes into contact with the cassette-shaped magnetic bubble memory and a discharge occurs, the discharge current is discharged without flowing into the bubble memory device.

Therefore, the device of the present invention is safe against the discharge of static electricity carried by a worker, and even if such discharge occurs, the initial characteristics of the device itself and the previously written information can be maintained.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS A cassette memory according to an embodiment of the present invention will be explained below using the drawings.

FIG. 2 is a perspective view showing the external appearance of a cassette memory according to an embodiment of the present invention, and FIG. 3 is a perspective view showing a bubble memory device etc. housed in the cassette case of the cassette memory and a conductive film-covered sheet separated from each other. FIG. 4 is an exploded perspective view of the cassette case.

In FIG. 2, in which the same reference numerals are used for parts common to those in the previous figure, 21 is a cassette memory, 26 is a cassette case corresponding to the above-mentioned cassette case 7;
7 is a ground terminal corresponding to the ground terminal 12 mentioned above.

A cassette case 16 housing the bubble memory device 2, connector 3, wiring board 6, ground terminal 27, protective conductor 13 (Fig. 3), etc. is attached to the upper case 2.
2, lower case 23, and U-shaped metal plate 2 in side view
4, and a plurality of screws 25 that fix the metal plate 24 to the cases 22 and 23, and the ground terminal 2
A portion of 7 is exposed at the middle of a groove 29 formed at the joint between the upper case 22 and the lower case 23.

In FIG. 3, the protective conductor 13 is the inner surface 2 of an insulating sheet 28 made of flexible polyimide or the like.
A metal film 28c is attached to the bubble memory device 8b, and its size is such that it covers at least the front surface (top surface) and back surface (bottom surface) of the bubble memory device 2. Therefore, the outer surface 28a of the electrically insulating insulating sheet 28 faces the metal plate 24, and the electrically conductive inner surface 28b faces the bubble memory device 2.
and the lower surface of the wiring board 6.

On the other hand, the wiring board 6 uses a flexible printed wiring board with a conductor pattern sandwiched between insulation sheets.
A series of ground patterns 6b are exposed on the tongue piece 6a projecting laterally and on a predetermined portion of the lower surface (not shown). A ground terminal 27 is soldered to the ground pattern 6b via a lead wire 30, and a predetermined portion of the lower surface is in contact with the metal film 28c on the inner surface 28b of the insulating sheet 28 when housed in the cassette case 26. It's summery.

In FIG. 4, an upper case 22 and a lower case 23, each having a substantially concave cross section, have openings 22a and 23a facing the front or back surface of the device 2, and are firmly attached to each other with the device 2 and the connector 3 sandwiched between them. By bonding (bonding), the device 2 and the connector 3 are fixed in position, but at that time, a portion of the ground terminal 27 is exposed to the notch 22b provided in the side wall of the upper case 22.

On the other hand, the metal plate 24 is fixed by screws 25 passing through the through-holes 24a being screwed into the screw holes 22c of the upper case 22 or the screw holes 23b of the lower case 23. 24
By removing the chip, it is possible to check the recording sheet attached to the surface of the device 2, for example, the sheet in which the defective loop number of the chip in question is written.

The cassette memory 21 is held by the metal plate 24 in the hand and is attached to and detached from a device equipped with a connector into which the connector 3 is inserted. The worker is charged with static electricity, and the discharge current of the static electricity that flows when inserting the cassette memory 21 into the device is as follows:
It is discharged to the outside through the metal film 28c of the insulating sheet 28, the wiring board 6, the lead wire 30, and the ground terminal 27 without flowing into the device 2.

〔Effect of the invention〕

As explained above, according to the present invention, even if an object charged with static electricity comes into contact with the bubble memory device, the electric charge is discharged without passing through the bubble memory device. especially,
If the above-mentioned cassette memory is left in an area where there are no conductors around it, the static electricity charged on the cassette case will be dissipated into the air, and if it is discharged into an area where there are conductors nearby, Static electricity charged on the cassette case is directly discharged to the conductor. Therefore, the effect of eliminating damage to the device and damage to written information due to the discharge is extremely large.

[Brief explanation of drawings]

Fig. 1 is a schematic side sectional view showing the basic configuration of the present invention, Fig. 2 is a perspective view showing the external appearance of a cassette memory according to an embodiment of the invention, and Fig. 3 is a cassette memory housed in a cassette case. FIG. 4 is an exploded perspective view of the cassette case, and FIG. 5 is a schematic side sectional view of a conventional cassette memory. . 1 to 5, 1, 11, and 21 are cassette memories, 2 is a bubble memory device, 3 is an external connection connector, 4 is a contact, 5 is a lead terminal, 6 is a wiring board, 6a is a tongue piece, 6b is the ground pattern, 7, 26 is the cassette case, 12, 2
7 is a ground terminal, 13 is an electrostatic protection conductor, 22
is the upper case, 23 is the lower case, 22a, 23
a is an opening, 22b is a notch, 22c and 23b are screw holes, 24 is a metal plate, 24a is a through hole, 25 is a screw, 28 is an insulating sheet, 28a is an outer surface, 28b is an inner surface, 28c is a metal film, and 29 is a A groove and 30 indicate a lead wire.

Claims (1)

[Claims] 1. At least a bubble memory device 2 having a bubble memory chip, a bias magnet drive coil, etc. within a soft magnetic metal shield, an external connection connector 3, contacts 4 of the connector 3, and the device. a wiring board 6 connecting the lead terminal 5 of the device 2; and an electrostatic protection conductor 13 of the device 2;
It comprises a cassette case 7 that accommodates the wiring board 6, the device 2, the connector 3, and the conductor 13, and a ground terminal 12 that is connected to the outside earlier than the external connection of the contact 4, and the conductor 13 is connected to the outside. In the cassette-shaped magnetic bubble memory connected to the ground terminal 12 in the cassette case 7, the conductor 13 is formed by depositing a metal film 28c on one side of the insulating sheet 28, so that the metal film 28c is on the inside. A cassette-shaped magnetic bubble memory characterized in that the device 2 is housed in the cassette case 7 in a state where the device 2 is wrapped together with the wiring board 6.